Research

Harvestmen males (Neopilionidae) brandish large chelicerae which they use to access females. While we currently know little about this group, harvestmen promise to be an exciting and unique model to study the evolution of animal weaponry. The largest males of this group boast what is perhaps the animal kingdom’s most extreme weaponry; male chelicerae may comprise over 50% of the total body mass. Some species exhibit a polymorphism where conspecific males have strikingly different weapon morphs, with variation in both size and shape.

Male Neopilionidae from Southland, NZ with extremely large chelicerae

I am combining behavioural, morphological, and physiological approaches to explore the evolution of exaggerated chelicerae in male harvestmen in the Neopilionidae. My PhD project first seeks to answer questions about weapon evolution by observing contest and courtship behaviour of the species Forsteropsalis pureora. The project will then examine the evolution and maintenance of a weapon polymorphism by testing for mechanistic, reproductive, and metabolic costs of extreme weaponry in these two species.

Female Neopilionidae from Southland, NZ. Note the reduced chelicerae on this female compared to the male above. These specimens were collected together in a crevice on the rock wall of a waterfall.

Mud dauber wasp females may capture 5-25 spiders in a single day to provision one egg. Females paralyze spider prey and pack them into a mud nest. The hatched larva consumes the paralyzed spiders, pupates, and emerges as an adult. This unique life history strategy provides us with an excellent system with which to examine foraging behaviour and decision-making because we are able to collect paralyzed spider “prey items” completely intact. The first project of my MSc at the University of Florida documented individual specialization in the mud dauber wasp, Sceliphron caementarium. Females from a single population provision their nests with different spider prey, despite having access to the same spiders. See my open access article under Publications.

I have more questions about mud daubers now than ever, so I hope to be able to return to this system at some point.